Fig. 1.

NleH inhibits C. difficile toxin B-mediated cell death. Cell viability counts were determined during infection of HeLa cells with wild-type EPEC, EPEC ΔnleH1ΔnleH2 and the complemented strain ΔnleH1ΔnleH2(pICC443). Uninfected and EPEC ΔescN-infected cells were used as controls. Cells were left unchallenged (white bars) or challenged (black bars) with 4 ng TcdB ml⁻¹ for 18 h (a) or 4 μg TcdB ml⁻¹ for 4 h (b). In the absence of toxin, cell viability was significantly reduced following infection with EPEC ΔnleH1ΔnleH2 compared with uninfected cells or cells infected with wild-type EPEC.